/*
 * Copyright (C) 2013  P. J. McDermott
 *
 * This file is part of Dodge Balls
 *
 * Dodge Balls is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Dodge Balls is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Dodge Balls.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <stddef.h>
#include <zlib.h>
#include "compression.h"
#include "output.h"

static void
_db_zlib_err(int status)
{
	switch (status) {
		case Z_OK:
		case Z_STREAM_END:
			break;
		case Z_MEM_ERROR:
			db_err("zlib error: out of memory");
			break;
		case Z_VERSION_ERROR:
			db_err("zlib error: incompatible library version");
			break;
		case Z_STREAM_ERROR:
			db_err("zlib error: invalid stream");
			break;
		case Z_NEED_DICT:
			db_err("zlib error: need dictionary");
			break;
		case Z_DATA_ERROR:
			db_err("zlib error: corrupted data");
			break;
		case Z_BUF_ERROR:
			db_err("zlib error: buffer error");
			break;
		default:
			db_err("zlib error: unknown");
			break;
	}
}

void
db_decompress(char *src, size_t src_len, char *dest, size_t dest_len)
{
	z_stream d_stream;

	d_stream.zalloc    =           Z_NULL;
	d_stream.zfree     =           Z_NULL;
	d_stream.opaque    =           Z_NULL;
	d_stream.next_in   = (Bytef *) src;
	d_stream.avail_in  =           src_len;
	d_stream.next_out  = (Bytef *) dest;
	d_stream.avail_out =           dest_len;

	db_dbg("Initializing inflation stream...");
	_db_zlib_err(inflateInit2(&d_stream, 15 + 32));

	db_dbg("Inflating %zu bytes into up to %zu bytes...", src_len, dest_len);
	_db_zlib_err(inflate(&d_stream, Z_NO_FLUSH));

	db_dbg("Ending inflation stream...");
	_db_zlib_err(inflateEnd(&d_stream));
}